Certain n-benzoyl-1,2,5,6-tetrahydropyridines

ABSTRACT

COMPOUNDS OF THE FORMULA   1-(R-C6H4-CO-)-1,2,3,6-TETRAHYDROPYRIDINE   WHEREIN R IS ALKYL HAVING 1 TO 4 CARBON ATOMS, ALKOXY HAVING 1 TO 4 CARBON ATOMS OR HALOGEN AND THEIR USE AS INSECT REPELLENTS.

United States Patent Office 3,749,730 Patented July 31, 1973 ABSTRACT OF THE DISCLOSURE Compounds of the formula wherein R is alkyl having 1 to 4 carbon atoms, alkoxy having 1 to 4 carbon atoms or halogen and their use as insect repellents.

This invention relates to certain novel substituted benzoyl piperideines and their use as insect repellents. The compounds of this invention has the formula wherein R is alkyl having 1 to 4 carbon atoms, preferably methyl, more preferably m-methyl; alkoxy having 1 to 4 carbon atoms, preferably methoxy, more preferably methoxy or halogen, preferably chlorine or fluorine.

The compounds can be prepared -by reacting a compound of the formula in which R is as defined with the compound 1,2,3,6 tetrahydropyridene having the formula The 1,2,3,6 tetrahydropyridene is slowly added to a solution of the substituted benzoyl chloride in a solvent such as chloroform at a temperature under 30 C. in the presence of HCl acceptor such as triethylamine.

Preparation of the compounds of this invention is illustrated by the following example:

EXAMPLE I 1-(in-toluoyl)-3-piperideine 7.7 grams (0.05 mole) in toluoyl chloride is dissolved in 100 milliliters chloroform. 4.6 milliliters 1,2,3,6 tetrahydropyridene and 8.0 milliliters triethyl amine are added to the solution over a minute period with cooling keeping the temperature under 30 C. The mixture is allowed to stand for 3 hours. The reaction product is recovered by washing the mixture with 100 milliliters water and 100 milliliters saturated NaHCO solution. The washed mixture is dried over MgSO, and evaporated to yield 10.5 grams of a compound corresponding to the desired structure. N 1.5530. The structure is confirmed by n.m.r.

l-(o-fluorobenzoyl)-3-piperidene, l-(o-chlorobenzoyl)- 3 piperideine, l-(p-bromobenzoyl)-3-piperideine, l-(pbutylbenzoyl) 3 piperidene, l-(o-methoxybenzoyl)-3- piperidene, and l (m-butoxybenzoyl)-3-piperidene are also prepared in a similar manner according to the general method described for preparing the compounds of this invention.

The following test description and results illustrate the use of the compounds of this invention as insect repellents.

Housefly repellent test Each test cage consists of a tule-covered number 116, 16 oz. waxed paper Dixie cup with two 4 oz. waxed paper condiment cups stapled on opposite sides of the upper, interior perimeter. One of the cups contains a sugar cube saturated with 0.8 milliliter of acetone containing a specific concentration of the test repellent and allowed to dry. The second condiment cup contains a water-saturated cotton plug. After each cube has been treated and allowed to dry, it is carefully weighed and placed in the test cage. One hundred houseflies of mixed sexes are then placed in the cages and all of the cages are placed on a 1 /2 r.p.m. turntable. This procedure keeps the flies in random distribution within the cage and eliminates their gathering on the cage walls due to a phototropic response to outside light sources, which gathering has been found to give a false appearance of repellency by the sugar cube. At daily intervals after treatment, the flies in each cage are anesthesized with C0 The cube is removed, reweighed and the percentage weight loss of the cube (due to consumption by the flies) is recorded. The cubes with the least weight loss are considered to be the most repellent to the fiies. Table I contains a summary of the first, second, and fourth day readings for the candidate repellent at 1% concentration.

TABLE I [Percentage weight loss of repellent treated sugar cubes due to consumption by houseflies1% concentration] Compound 24 hrs. 48 hrs. 96 hrs.

l-(m-toluoyl)-3-piperideine 02 6. 20. 0 l-(o-fluorobenzoyl)-3-piperidene 16 10. 3 28.1 l-(o-chlorobenzoyl)-3-piperideine 1. 7 10.7 26. 4 Acetone only (control) 10.3 21. 4 45. 3

I claim: 1. A compound of the formula References Cited UNITED STATES PATENTS 3,209,006 9/1965 Wragg et al. 260-297 R ALAN L. ROTMAN, Primary Examiner US. Cl. X.R. 

